The present invention relates to a tarp enclosure system used for covering the upper surface of a truck bed or railcar, and more particularly a tarp enclosure system which is suitable for use with removable trailer bows and which may be extended or retracted from a remote location by a user standing on the ground.
In the haulage of bulk goods such as heavy machinery, steel rods and coils, sod and non-prepackaged consumer goods, it is often desirable to ship the goods via a flat bed truck or train trailer. Conventional truck or train trailers consist of a flat rectangular trailer bed surface characterized by parallel longitudinal sides and lateral ends. It is known to cover the goods on the trailer with a tarp to protect the goods from exposure to the elements and, in the case of goods such as sod, to prevent debris and/or detritus from blowing from the trailer. In the most basic construction, the trailer is provided with a number of removable U-shaped metal bows which are used to support the flexible cover or tarp above the load while protecting it from the environment. Typically, the bows consist of a single length of bent tubular steel stock. The ends of the bows are removably secured in a complementary sized slot or hole formed along the opposing longitudinal sides of the trailer bed.
Conventionally, the trailer beds are enclosed by manually securing the tarp in place stretched over both the bows and the load on the trailer by means of shock cords and/or hold-down straps. When loading or unloading the trailer, the shock cords used to secure the flexible tarp in place stretched over the bows are manually released and the cover manually pulled aside. Once the cover has been removed, the driver or warehouseman removes the bows by pulling their ends from the slots in the trailer bed. Once removed, access to the surface of the trailer bed may be obtained along one or both of its longitudinal sides. Thereafter, the goods to be shipped are placed on the bed and the bows and cover are repositioned.
The manual positioning of the tarp typically requires that the driver or individual loading the trailer climb overtop of both the trailer bed and the load, while simultaneously positioning the tarp and re-securing it in place with the shock cords. The manual positioning of the tarp is both time consuming and inefficient. Furthermore, in physically climbing overtop of the loaded goods, there is increased risk of injury if, for example, the individual falls off the trailer and/or trips or falls on the loaded goods.
In an effort to simplify the manual loading and/or unloading of trailers, various individuals have proposed tarp covering or enclosure systems. U.S. Pat. No. 5,152,575 to DeMonte et al discloses a tarp enclosure system which incorporates a number of horizontally slidable U-shaped bows which are used to collapse or extend a cover over the top of a truck trailer bed in an accordion-like manner. The Wahpeton Canvass Company of North Dakota has sold in conjunction with its trade mark SHURCO(trademark) various enclosure systems which are adapted to be rolled or unrolled horizontally over the open top of dump truck and grain trailer bins.
Heretofore, however, the marketplace has achieved little or no success in providing vertically retractable tarp systems which are adapted to permit lateral access to a flat truck or railcar trailers which have bows which are either permanently secured to the trailer bed, or which are removable for loading and unloading goods thereon.
Accordingly, it is an object of the invention to provide a retractable trailer enclosure system for use in covering at least part of the upper surface of the bed of a truck or railcar trailer, and which has tarp or cover supporting bow members which are either permanently secured to the trailer bed, or which are removable so as to permit loading and/or unloading of goods onto the trailer from at least one of its lateral sides.
Another object of the invention is to provide a retractable trailer enclosure system which includes a flexible tarpaulin or cover, hereinafter also generally referred to as a tarp, which may be selectively vertically and/or horizontally retracted or extended so as to expose or cover the upper surface of a truck or train trailer bed by a user standing beside the trailer or from another remote location.
Another object of the invention is to provide a retractable trailer enclosure system which includes a flexible tarp which when extended over the trailer, is adapted to provide a substantially fluid-seal tight arrangement between the longitudinal sides of the trailer bed and the tarp.
Another object of the invention is to provide a retractable trailer enclosure system which may be vertically retracted along one longitudinal side of a flat truck or rail car trailer, so as to permit the loading or unloading of goods thereon by a conventional fork lift, tractor, crane or the like.
A further object of the invention is to provide in combination a trailer and a retractable tarpaulin system which includes one or more U-shaped bows and a flexible cover or tarp which may be selectively extended or retracted to cover or uncover the U-shaped bows of a trailer, and which when retracted, permits the bows to be manually lifted clear of the trailer to facilitate its loading or unloading.
To achieve at least some of the aforementioned objects, the present invention provides a retractable trailer enclosure system for use in covering at least part of the bed of a truck trailer, railcar trailer or the like, hereinafter collectively referred to as a xe2x80x9ctrailerxe2x80x9d. Typically, the trailer has a flat horizontally extending bed characterized parallel and longitudinally elongated sides, lateral front and rear ends and a generally flat upper surface.
One or more bows are vertically mounted on the trailer bed and arc used to support a flexible cover above the transported goods, so as to prevent rain, snow and/or wind damage to the goods, as well as preventing debris from blowing off of the trailer during transportation. The bows are formed from lengths of straight, bent or welded steel or aluminum stock and when assembled have a generally inverted U-shape. The bows have a width selected to span substantially the lateral width of the trailer bed and have a height which is selected having regard to the desired cargo to be moved, and which in the typical case is selected at between 4 and 10 feet, and more typically between about 6 and 8 feet. In a more economical construction, the bows are provided as part of a welded lattice, permanently secured to the trailer bed. More preferably, however, one or more of the bows are removable, allowing the trailer roof to be largely opened up to facilitate loading and/or unloading of the goods. Removable bows are mounted to the trailer in a number of manners, as for example, with the lower ends of each vertical side of the bows being received in a complementary sized socket formed in the upper surface of the trailer bed.
Although not essential, at least one and preferably two to three bows are supported by a removable truss member. The truss members consist of a vertically extending support which extends from the trailer bed, upwardly to engagingly support an underside of the bed. An adjustable T-support provided on the truss member is brought into contact with a bow, wedging the truss member in place as a vertical support. The T-support is adjustable in height and is configured to enable the truss members to be moved into a desired position under a selected bow, having regard to the positioning and form of the goods to be shipped.
The cover or tarpaulin of the trailer enclosure system may be retracted to expose and permit access to the trailer bed surface, or extended to cover the trailer bed together with any goods which are positioned thereon for transport. An elongated spindle is provided which is mounted to the trailer by means of a spindle mount assembly. As will be described, the spindle is used to wind the tarp, coiling or uncoiling it thereabout in its retraction or extension. The cover when extended is stretched over the bows with one of its longitudinal edges secured to the spindle. The spindle is elongated along its longitudinally elongated axis, and although not essential, preferably has a length generally corresponding to the length of the portion of the trailer bed to be covered. More preferably, the spindle and cover each have a longitudinal length corresponding to that of the trailer sides.
The spindle is movably supported in an orientation with its spindle axis generally parallel to the upper surface of the trailer bed by the spindle mount. More preferably, the spindle mount is used to secure the spindle so that it may be moved along a generally arcuate extending path or corridor. In a simplified construction, the spindle mount consists of a pair of spaced pivot rods. Each of the pivot rods is elongated so as to extend from a first end portion to a second distalmost end portion. The first end portion of each of the pivot rods is secured to an associated pivot aligned with a pivot axis which preferably is also oriented parallel to the spindle axis. The pivot rods, for example, may be mounted to the trailer such that the second end of each rod may be movable from a generally lateral orientation along the arcuate path or corridor about the pivot axis. The spindle is thus movable with the pivot rods from a lowered position wherein the second end of each of the pivot rods is moved adjacent to the first longitudinal side of the bed, and a retracted position wherein the distal end of the pivot rods is moved radially about the pivot axis therefrom.
Each of the pivot rods is more preferably provided as a telescoping rod with the distalmost end being movable radially outwardly from the pivot axis. In this regard, the arcuate corridor along which the spindle moves may be defined as the path between the outwardmost radial path along which the distalmost end travels when fully extended, and an innermost radial path along which the distalmost end travels when fully retracted. Preferably, a tensioner is provided to resiliently bias the distalmost end to the retracted position.
A manual, electric or other power drive is used to selectively rotate the spindle to thereby extend or retract the tarp over the bows. When the tarp is in an initial extended position covering the trailer bed and bows, the initial rotation of the spindle about its spindle axis results in the winding of the cover about the spindle. As the cover is coiled about the spindle, the spindle is drawn by advancing along the tarp in movement over the arcuate path. In this manner, the tarp may be retracted to expose the trailer bed and bows simply by having it coil about the spindle upon its rotation. In a similar manner by reversing the direction of rotation of the spindle, the tarp is unwound to recover the trailer bed and bows.
The trailer may be provided with front and rear bulkheads, each consisting of a vertical panel spanning across the front and rear lateral ends of the trailer. The bulkheads may be formed of metal and/or wood having a square or generally rectangular shape and most preferably having a profile generally corresponding to that of the U-shaped bows. The bulkheads, although not essential, provide additional safety and assist in preventing a load from shifting in the front to back direction as the truck or railcar brakes.
Although not essential, a spring or other biasing element may be provided to assist in moving the spindle along the arcuate corridor. In another construction, gearing may be used to facilitate the movement of the spindle along its arcuate path. In one possible construction, a toothed pinion or other gear may be secured to one or both ends of the rotatable spindle, and a complementary sized rack is secured over at least part of the upper surface of the adjacent bulkhead. The rotation of the spindle thus moves the gear along the rack to assist in guiding the spindle in movement, as the cover is coiled or uncoiled.
Although not essential, it is most preferable that the tarp enclosure system includes a pair of elongated spindles, each mounted to an associated spindle mount and secured to a respective longitudinal edge of the tarp. Such a construction advantageously permits access to either side of the truck trailer bed.
Accordingly in one aspect, the present invention resides in a retractable trailer enclosure system for covering at least part of the bed of a truck trailer characterized by longitudinally elongated parallel sides and laterally extending ends, the enclosure system comprising,
a flexible cover having a size selected to overly said part of the trailer bed,
a spindle elongated along an axis and having a length generally corresponding to the length of a first one of said trailer sides,
a spindle mount for movably supporting the spindle in a substantially horizontal orientation generally parallel to the longitudinal direction of said first side, the spindle mount including a pair of pivot rods,
a first one of said pivot rods being pivotally secured at an associated pivot proximate a first one of said lateral end of said bed,
the second other one of said pivot rods being pivotally secured at an associated pivot proximate to the second other one of said lateral ends,
each of the first and second pivot rods extending from said associated pivot laterally to a distalmost end and further comprising a spindle coupling at said distalmost end thereof, said spindle coupling rotatably supporting said spindle, each of said pivot rods comprises a telescoping rod having an extendible member which is movable between a retracted position spaced towards said associated pivot and an extended position moved outwardly therefrom, the spindle coupling being coupled to the extendible member,
a drive for selectively journaling the spindle in rotational movement about its axis,
the cover being secured along an edge portion to the spindle whereby the rotation of the spindle by said drive winds or unwinds the cover about the spindle to retract or extend the cover over said part of the bed.
In another aspect, the present invention resides in a retractable enclosure system for covering the upper surface of a longitudinally elongated bed of a railcar or truck trailer comprising,
a flexible cover having a size selected to overly at least part of the bed,
a spindle elongated along an axis and having a length substantially corresponding to the longitudinal length of the bed,
a spindle mount for movably supporting the spindle in an orientation substantially parallel to the upper surface of the bed, the spindle mount comprising a pair of pivot rods each being elongated from a first end portion to a second end portion, the second portion of each of said pivot rods comprises a telescoping portion movable between a fully retracted position spaced towards said first end portion and an extended position moved distally therefrom,
the first end portion of a first one of said pivot rods being mounted at an associated first pivot adjacent to a first lateral end of said bed,
the first end portion of the second other one of said pivot rods being mounted at an associated second pivot adjacent to the second lateral end of said bed,
the spindle being rotatably supported by the second end portions of each of the pivot rods,
a drive operable to selectively journal the spindle in rotational movement about its axis, and wherein the cover is secured along an edge portion to the spindle whereby the rotation of the spindle by the drive winds or unwinds the cover about the spindle to retract or extend the cover over the bed.
In a further aspect, the present invention resides in a retractable trailer enclosure system for covering a trailer bed characterized by longitudinally elongated first and second parallel sides and laterally extending ends, the enclosure system comprising,
a flexible cover having a size selected to overly said trailer bed,
a first spindle elongated along a first spindle axis and having a length generally corresponding to the length of said first trailer side,
a first spindle mount for movably supporting the first spindle in an orientation generally parallel to the longitudinal direction of said first side, the first spindle mount including a pair of pivot rods each secured at an associated pivot and rotatable about a first pivot axis extending generally parallel to said first spindle axis,
each pivot rod extending from said associated pivot to a distalmost end and further comprising a first spindle coupling at said distalmost end thereof, said first spindle coupling rotatably supporting said first spindle,
a first drive for selectively journaling the first spindle in rotational movement about said first spindle axis,
a second spindle elongated along a second spindle axis and having a length generally corresponding to the length of said second trailer side,
a second spindle mount for movably supporting the second spindle in an orientation generally parallel to the longitudinal direction of said second side, the second spindle mount including a pair of pivot rods each secured at an associated pivot and rotatable about a second pivot axis extending generally parallel to said second spindle axis,
each pivot rod extending from said associated pivot to a distalmost end and further comprising a second spindle coupling at said distal most end thereof, said second spindle coupling rotatably supporting said second spindle,
a second drive for selectively journaling the second spindle in rotational movement about said second spindle axis,
a first edge portion of the cover being secured to the first spindle, whereby the rotation of the first spindle by said first drive winds or unwinds the cover about the first spindle to retract or extend the cover over said first side of the bed,
a second edge portion of the cover being secured to the second spindle whereby the rotation of the second spindle by said second drive winds or unwinds the cover about the second spindle to retract or extend the cover over said second side of the bed.